fish vs solid food

fish and solid food both are nouns.

Word	Noun	Adjective	Verb	Adverb
fish	Yes	No	Yes	No
solid food	Yes	No	No	No

As nouns, solid food is a hypernym of fish; that is, solid food is a word with a broader meaning than fish:

fish: the flesh of fish used as food
solid food: any solid substance (as opposed to liquid) that is used as a source of nourishment

Other hypernyms of fish include food.

fish (noun)	solid food (noun)
any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills	any solid substance (as opposed to liquid) that is used as a source of nourishment
the flesh of fish used as food

fish (verb)	solid food (verb)
catch or try to catch fish or shellfish
seek indirectly